1. Field of the Invention
The present invention relates generally to an electrostatic discharge (ESD) device. More particularly, the present invention relates to an ESD device with a parasitic SCR structure having a controllable trigger voltage.
2. Description of Related Art
ESD devices have been widely used in integrated circuits to prevent damages caused by static electricity. Generally, the ESD device occupies a considerable chip area on which an integrated circuit (IC) is fabricated, which accordingly increases manufacturing cost. Furthermore, due to the transmission characteristic of conducting wires and generally a large dimension of the ESD device, current flowing through the ESD device is not uniform, which may affect the electric characteristics, such as a breakdown voltage of the ESD device.
The ESD devices with parasitic SCR structure are applied in many applications. How to achieve a stable and controllable trigger voltage of the parasitic SCR is still a main issue in the industry field.
Therefore, the ESD device having a controllable trigger voltage and improved electric characteristics is desired.